Connective Tissue Graft Versus Collagen Matrix

Buccal Soft Tissue Profile (BSP) Clinical Trial

Official title:

A Multicenter Randomized Controlled Study Comparing Connective Tissue Graft With Collagen Matrix to Re-establish Convexity at the Buccal Aspect of Single Dental Implants

Clinical Trial Details — Status: Active, not recruiting

Administrative data

• NCT number: NCT04210596
• Other study ID #: 18-178
• Secondary ID: BOF.STG.2019.000
• Status: Active, not recruiting
• Phase: N/A
• Start date: September 1, 2019
• Est. completion date: December 31, 2025

Study information

• Verified date: December 2023
• Source: University Ghent
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

Patients in need of a single implant in the premaxilla and presenting with a horizontal buccal soft tissue defect at the single tooth gap will be invited to participate in a multicenter RCT. Prior to surgery, a small-field low-dose CBCT is taken since a buccopalatal bone dimension of at least 6 mm at the central and crestal aspect of the single tooth gap is required to ensure complete embedding of an implant by bone. Sixty patients will be randomly allocated to the test group or control group in 6 centers. Each center receives 10 sealed envelopes (5 are internally labelled with 'test group' and 5 with 'control group').

For each patient a digital planning is performed in implant planning software and a tooth-supported surgical guide is fabricated. In the control group, a single implant is placed following flap elevation and surgical guide installation. Then, a CTG from the palate is positioned under the buccal mucosa to thicken the tissues. A provisional restoration is placed at the day of surgery, which is replaced by a permanent one 3m later. Patients in the test group are treated in the same way, yet a CM (Fibro-Gide®) is used instead of a CTG.

Changes in the buccal soft tissue profile are registered over time by superimposing intra-oral scans in SMOP® software.

Secondary outcomes included clinical, aesthetic and patient-reported outcomes.

Description:

Patients will be included in a multicenter RCT following screening and after having received written consent.

A sample size calculation using the Satterthwaite t-test was performed in SAS Power and Sample Size based on a comparison of mean change in BSP (primary outcome variable) from baseline to 1 year between the control group and test group. The calculation was based on finding a mean difference of at least 0.5 mm between these groups with a standard deviation of 0.5 mm for CTG and 0.7 mm for CM (as adopted from Zeltner et al. 2017). With alpha set at 0.05 and a power of 0.80, the sample size calculation indicated 25 patients to be included per group. To compensate for drop-outs, 30 patients would be treated with CTG and 30 would be treated with CM.

Clinicians and centers, randomization, allocation concealment and blinding Six experienced clinicians will treat 10 patients each. All clinicians are staff members of the Department of Periodontology and Oral Implantology at UGent - UZ Gent, who also work part-time in different private practices. The digital workflow, the implant placement protocol, the application of CTG and CM and the restorative protocol will be thoroughly discussed among the 6 clinicians in a training session before the start of the trial.

During the training session each clinician will receive 5 sealed envelopes internally coded as 'CTG' and another 5 as 'CM'. Just prior to surgery, a sealed envelope will be randomly selected and opened to reveal the treatment to be conducted. The measuring investigator will not be involved in the treatment of any of the patients and will be blinded to allow unbiased registrations.

Pre-operative digital planning A full digital workflow will be adopted for every patient. This implies the fabrication of a stereolythographic surgical guide on the basis of a 3D digital implant planning in designated software (NobelClinician, Nobel Biocare, Zürich, Switserland). A low-dose small-field Cone-Beam CT and intra-oral scan are required for this purpose. The same software will also be used to design a provisional acrylic crown, which will be adapted chairside immediately following surgery (Tempshell, Nobel Biocare, Zürich, Switserland).

Surgery Control group: soft tissue augmentation with CTG Patients start to take systemic antibiotics (Amoxicilline 1g) and anti-inflammatory medication (ibuprofen 600 mg) 1h pre-operatively. Following local anesthesia (Septanest special, Septodont, Saint Maur des Fossés, France) and oral disinfection (Corsodyl mouth rinse, GSK, Wavre, Belgium), a conventional mucoperiosteal flap will be raised. Thereupon, the surgical guide is positioned and a dental implant (NobelReplace CC PMC, Nobel Biocare, Zürich, Switserland) is installed. A CTG is harvested from the palatal mucosa in the premolar area by means of the single-incision technique as described by De Bruyckere et al. (2015) (fig. 1). The CTG is pulled into the envelope and fixed with two sutures (Seralon 6/0, Serag Weissner, Naila, Germany). Tension-free primary wound closure with the same suture material is pursued around a provisional acrylic crown. Post-op instructions include the intake of systemic antibiotics during 4 days (Amoxicilline 1g, two times a day), anti-inflammatory medication as deemed necessary by the patient and oral disinfection twice a day during 1 week. Then, sutures are removed. After 3 months, the provisional crown will be replaced by a permanent crown by the general dentist.

Test group: soft tissue augmentation with CM In the test group, no CTG is harvested as it will be replaced by CM (Fibro-Gide, Geistlich Biomaterials, Wolhusen, Switserland). Apart from that, all pre-op, surgical and post-op procedures are identical in the control group and test group.

Prior to surgery (baseline = t0), at 3 months (t1), 1 year (t2) and 5 years (t3) an intra-oral optical scan of the implant site and neighboring teeth will be taken (Trios, 3shape, Copenhagen, Denmark). The region of interest (ROI) will be defined on STL files with a trapezoid shape encompassing the following borders: 1 mm apical to the midbuccal soft tissue level (coronal), the mucogingival junction (apical) and 1 mm distance from the neighbouring tooth at both sides (mesial, distal). This ROI may vary between patients due to anatomical variation but will be kept constant in each patient and site over time. The STL images of baseline and follow-up will be superimposed and matched using the best-fit algorithm at the adjacent tooth surfaces. The linear changes in BSP will be measured in the middle of the ROI, calculated by the software and expressed in mm corresponding to the mean distance between the surfaces representing the evaluated time points (t0, t1, t2, t3).

All patients are scheduled for suture removal and oral hygiene instructions after 1 week with registration of:

Postoperative bleeding, Pain and amount of anti-inflammatory medication taken, Oedema and Hematoma.

After 3 months, 1 year and 2 years, all patients are scheduled for a clinical and radiographic follow-up visit, including registration of mesial and distal marginal bone level. Intra-oral radiographs will be taken using the long-cone parallel technique. Bone levels will be assessed and defined as the distance from the implant-abutment interface to the first bone-to-implant contact to the nearest 0.1 mm. Clinical parameters ,such as probing pockets depths (mm), plaque (presence or absence) and bleeding on probing (presence or absence) are registered as well as vertical soft tissue levels at the midbuccal aspect to the nearest 0.5 mm. White and Pink esthetics are assessed according to Furhauser.

Recruitment information / eligibility

• Status: Active, not recruiting
• Enrollment: 60
• Est. completion date: December 31, 2025
• Est. primary completion date: December 31, 2025
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

• at least 18 years old

• good oral hygiene defined as full-mouth plaque score = 25%

• presence of a single tooth gap in the anterior maxilla (15-25) with both neighboring teeth present

• failing tooth at least 3 months earlier removed

• class I defect at the single tooth gap as clinically assessed (buccopalatal loss of tissue with a normal apicocoronal ridge height)

• buccopalatal bone dimension of at least 6 mm at the central and crestal aspect of the single tooth gap to ensure complete embedding of an implant by bone.

Exclusion Criteria:

• systemic diseases

• smoking

• (history of) periodontal disease;

• untreated caries lesions

• need for horizontal bone augmentation at the time of implant placement

Related Conditions & MeSH terms

• Buccal Soft Tissue Profile (BSP)

Intervention

Procedure:
• Soft tissue augmentation at the buccal aspect of single implants
Soft tissue augmentation is performed following mucoperiosteal flap elevation at the buccal aspect of single implants. The connective tissue graft (control) or collagen matrix (test) is inserted in the buccal pouch and attached with monofilament sutures.

Locations

Country	Name	City	State
Belgium	Ghent University	Ghent	Oost-Vlaanderen

Sponsors (2)

Lead Sponsor	Collaborator
University Ghent	Osteology Foundation

Country where clinical trial is conducted

Belgium, 

References & Publications (19)

Burkhardt R, Hammerle CH, Lang NP; Research Group on Oral Soft Tissue Biology & Wound Healing. Self-reported pain perception of patients after mucosal graft harvesting in the palatal area. J Clin Periodontol. 2015 Mar;42(3):281-7. doi: 10.1111/jcpe.12357. Epub 2015 Feb 16. — View Citation

De Bruyckere T, Eeckhout C, Eghbali A, Younes F, Vandekerckhove P, Cleymaet R, Cosyn J. A randomized controlled study comparing guided bone regeneration with connective tissue graft to re-establish convexity at the buccal aspect of single implants: A one-year CBCT analysis. J Clin Periodontol. 2018 Nov;45(11):1375-1387. doi: 10.1111/jcpe.13006. — View Citation

De Bruyckere T, Eghbali A, Younes F, De Bruyn H, Cosyn J. Horizontal stability of connective tissue grafts at the buccal aspect of single implants: a 1-year prospective case series. J Clin Periodontol. 2015 Sep;42(9):876-882. doi: 10.1111/jcpe.12448. Epub 2015 Sep 16. — View Citation

Del Pizzo M, Modica F, Bethaz N, Priotto P, Romagnoli R. The connective tissue graft: a comparative clinical evaluation of wound healing at the palatal donor site. A preliminary study. J Clin Periodontol. 2002 Sep;29(9):848-54. doi: 10.1034/j.1600-051x.2002.290910.x. — View Citation

Eghbali A, Seyssens L, De Bruyckere T, Younes F, Cleymaet R, Cosyn J. A 5-year prospective study on the clinical and aesthetic outcomes of alveolar ridge preservation and connective tissue graft at the buccal aspect of single implants. J Clin Periodontol. 2018 Dec;45(12):1475-1484. doi: 10.1111/jcpe.13018. Epub 2018 Nov 5. — View Citation

Furhauser R, Florescu D, Benesch T, Haas R, Mailath G, Watzek G. Evaluation of soft tissue around single-tooth implant crowns: the pink esthetic score. Clin Oral Implants Res. 2005 Dec;16(6):639-44. doi: 10.1111/j.1600-0501.2005.01193.x. — View Citation

Hammerle CH, Araujo MG, Simion M; Osteology Consensus Group 2011. Evidence-based knowledge on the biology and treatment of extraction sockets. Clin Oral Implants Res. 2012 Feb;23 Suppl 5:80-2. doi: 10.1111/j.1600-0501.2011.02370.x. Erratum In: Clin Oral Implants Res. 2012 May;23(5):641. — View Citation

Huber S, Zeltner M, Hammerle CHF, Jung RE, Thoma DS. Non-interventional 1-year follow-up study of peri-implant soft tissues following previous soft tissue augmentation and crown insertion in single-tooth gaps. J Clin Periodontol. 2018 Apr;45(4):504-512. doi: 10.1111/jcpe.12865. Epub 2018 Feb 1. — View Citation

Naenni N, Bienz SP, Benic GI, Jung RE, Hammerle CHF, Thoma DS. Volumetric and linear changes at dental implants following grafting with volume-stable three-dimensional collagen matrices or autogenous connective tissue grafts: 6-month data. Clin Oral Investig. 2018 Apr;22(3):1185-1195. doi: 10.1007/s00784-017-2210-3. Epub 2017 Sep 18. — View Citation

O'Leary TJ, Drake RB, Naylor JE. The plaque control record. J Periodontol. 1972 Jan;43(1):38. doi: 10.1902/jop.1972.43.1.38. No abstract available. — View Citation

Seibert JS. Reconstruction of deformed, partially edentulous ridges, using full thickness onlay grafts. Part I. Technique and wound healing. Compend Contin Educ Dent (Lawrenceville). 1983 Sep-Oct;4(5):437-53. No abstract available. — View Citation

Tan WL, Wong TL, Wong MC, Lang NP. A systematic review of post-extractional alveolar hard and soft tissue dimensional changes in humans. Clin Oral Implants Res. 2012 Feb;23 Suppl 5:1-21. doi: 10.1111/j.1600-0501.2011.02375.x. — View Citation

Thoma DS, Buranawat B, Hammerle CH, Held U, Jung RE. Efficacy of soft tissue augmentation around dental implants and in partially edentulous areas: a systematic review. J Clin Periodontol. 2014 Apr;41 Suppl 15:S77-91. doi: 10.1111/jcpe.12220. — View Citation

Thoma DS, Naenni N, Benic GI, Hammerle CH, Jung RE. Soft tissue volume augmentation at dental implant sites using a volume stable three-dimensional collagen matrix - histological outcomes of a preclinical study. J Clin Periodontol. 2017 Feb;44(2):185-194. doi: 10.1111/jcpe.12635. Epub 2017 Jan 3. — View Citation

Thoma DS, Zeltner M, Hilbe M, Hammerle CH, Husler J, Jung RE. Randomized controlled clinical study evaluating effectiveness and safety of a volume-stable collagen matrix compared to autogenous connective tissue grafts for soft tissue augmentation at implant sites. J Clin Periodontol. 2016 Oct;43(10):874-85. doi: 10.1111/jcpe.12588. Epub 2016 Aug 12. — View Citation

Tonetti MS, Jepsen S; Working Group 2 of the European Workshop on Periodontology. Clinical efficacy of periodontal plastic surgery procedures: consensus report of Group 2 of the 10th European Workshop on Periodontology. J Clin Periodontol. 2014 Apr;41 Suppl 15:S36-43. doi: 10.1111/jcpe.12219. — View Citation

Van der Weijden F, Dell'Acqua F, Slot DE. Alveolar bone dimensional changes of post-extraction sockets in humans: a systematic review. J Clin Periodontol. 2009 Dec;36(12):1048-58. doi: 10.1111/j.1600-051X.2009.01482.x. — View Citation

Zeltner M, Jung RE, Hammerle CH, Husler J, Thoma DS. Randomized controlled clinical study comparing a volume-stable collagen matrix to autogenous connective tissue grafts for soft tissue augmentation at implant sites: linear volumetric soft tissue changes up to 3 months. J Clin Periodontol. 2017 Apr;44(4):446-453. doi: 10.1111/jcpe.12697. Epub 2017 Feb 11. — View Citation

Zucchelli G, Mounssif I, Mazzotti C, Montebugnoli L, Sangiorgi M, Mele M, Stefanini M. Does the dimension of the graft influence patient morbidity and root coverage outcomes? A randomized controlled clinical trial. J Clin Periodontol. 2014 Jul;41(7):708-16. doi: 10.1111/jcpe.12256. Epub 2014 May 8. — View Citation

* Note: There are 19 references in all — Click here to view all references

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	Changes in buccal soft tissue profile (BSP)	Volumetric analysis with designated software on the basis of intra-oral scans at fixed time points (absolute changes in mm, relative changes in %)	Pre-op, 3 months, 1 year, 2 years
Secondary	Changes in Probing pocket depth	Probing pocket depth (mm)	3 months, 1 year, 2 years
Secondary	Changes in Bleeding on probing	Bleeding on probing (score 0-4)	3 months, 1 year, 2 years
Secondary	Changes in Plaque Index	Plaque index (score 0-4)	3 months, 1 year, 2 years
Secondary	Changes in radiographic outcomes	marginal peri-implant bone loss (mm)	3 months, 1 year, 2 years
Secondary	Patient-reported outcome measures	Assessment of pain (VAS)	1 week
Secondary	Patient-reported outcome measures	oedema (VAS)	1week
Secondary	Patient-reported outcome measures	bleeding (VAS)	1 week
Secondary	Patient-reported outcome measures	hematoma (VAS)	1 week
Secondary	Patient-reported outcome measures	aesthetic evaluation by patients (VAS)	1 week
Secondary	Patient-reported outcome measures	aesthetic evaluation by patients (VAS)	3 months
Secondary	Patient-reported outcome measures	aesthetic evaluation by patients (VAS)	1 year
Secondary	Patient-reported outcome measures	aesthetic evaluation by patients (VAS)	2 years
Secondary	Patient-reported outcome measures	willingness to undergo again (VAS)	1 week
Secondary	Patient-reported outcome measures	willingness to undergo again (VAS)	3 months
Secondary	Patient-reported outcome measures	willingness to undergo again (VAS)	1 year
Secondary	Patient-reported outcome measures	willingness to undergo again (VAS)	2 years
Secondary	Aesthetic outcome as assessed by care providers	Pink Esthetic Score (0-14)	1 year
Secondary	Aesthetic outcome as assessed by care providers	Pink Esthetic Score (0-14)	2 year
Secondary	Aesthetic outcome as assessed by care providers	WhiteEsthetic Score (0-10)	1 year
Secondary	Aesthetic outcome as assessed by care providers	White Esthetic Score (0-10)	2 years
Secondary	Surgery time	Time needed to complete the contour augmentation procedure	At Surgery
Secondary	Primary stability	Primary stability after implant placement (Ncm)	At Surgery
Secondary	Incremental cost-effectiveness ratio	Difference in cost divided by the effect of the different procedures	baseline - 2 years